Weird Science finds that murderous necrophiliac frogs make great dads

And those frogs might not care where their eyes end up.

If you're going to kill your partner, you don't want to waste all the energy you put into courtship. Say you're a frog. It's that time of year. You and a half-dozen other males have found some lucky female sitting in a pond. After a long, exhausting fight, you've finally found yourself ready to mate with the female. Just one problem: during the scuffle that got you there, she drowns. Oops. Now all that energy has gone to waste, right?

Not necessarily! As the authors of a study of an Amazonian frog species note, "Such occurrences are obviously detrimental to females, and may also cause a decrease in the reproductive success of males through depletion of energy without obtaining access to a live female." Fortunately, it's just these sorts of detrimental occurrences that evolution is extremely good at handling. In this case, the male frogs are able to give a dead female such a robust squeeze that it forces some of her eggs out, allowing a "successful" necrophilial mating. "This behavior can minimize losses to both partners," the authors helpfully note.

For the frogs, the eyes have it. We all know how the eye works: picks up light, converts it to nerve impulses, sends it down the optic nerve to the brain, where special areas dedicated to processing it. So, what happens if you have an extra eye? It's actually relatively easy to arrange in frogs, where the primordial eye can be removed from one embryo and transplanted to another. Pretty much anywhere you put it, it will go on to form a normal looking eye (excepting that it may be on the animal's backside, of course). But, in their unusual location, they don't have a chance to form normal connections to the brain.

It may not matter that much, if the results of this paper are to be believed. The researchers simply relocated the animal's eyes, so that their normal ones were missing but they had new ones located in other areas of the body. Somehow, even without the connections to the appropriate areas of the brain, some of these animals could be trained to respond to light. And in keeping with the mad scientist theme, the training involved having them associate light with electric shocks. In any case, it's not at all clear what's sending information to the right parts of the brain that form aversive memories.

Empathy, as seen on TV. The boom in crime dramas may be having an unexpectedly positive effect: more people are willing to help out crime victims. As usual for studies of this sort, the population being queried was a small horde of local undergraduates. They were quizzed on their attitudes and media viewing habits, then asked about their willingness to intervene in cases where a sexual assault was happening. "Exposure to primetime crime dramas were associated with participants' intentions to intervene in a sexual assault," the authors conclude. They note, "These popular programs increasingly demonstrate the emotional and physical effect of sexual assault on its victims, and in some instances they depict individuals being rewarded for intervening to prevent or stop an assault in progress."

Evolutionary adaptations to spookiness. Owls are magnificent birds, but they do have an eerie ability to twist their heads around to an uncanny degree, leaving them able to observe areas directly behind them. Even if humans could perform this trick without straining their spinal cord, it would cause them to pass out by choking off the arteries supplying their brain. Now, we know this ability required extensive adaptations, including enlarged channels through the vertebrae and the ability of the arteries to balloon out to several times their normal size. So, the owl can do its thing while remaining fully conscious.

(Editor's note: OK, maybe not especially weird, but it gives me a chance to link a video that truly is.)

Rotate your owl for science!

Could you pick up some milk when you're out rioting? "People tend to prefer shopping locally, but are prepared to travel further for a larger or more attractive retail center, and the same appears to be true of rioters." Those are the words of one member of a research team at the University College of London, who built a mathematical model of that city's recent riots. They came to three conclusions: the decision to riot spreads like a contagion, the response of the police makes a difference, and, in general, people don't like to travel that far to participate in a riot. Overall, the authors say their model can predict how riots are likely to develop given a detailed map of a city. Therefore, it can determine where police resources are best applied.

I find the Crime-dramas-creating empathy to be only mildly interesting and not that surprising. We've known for a while that Tv, whether by media or actual TV shows, affects those who watch it, so it stands to reason that those who watch Crime-drama shows would pick up on the 'Crime is bad, help those in need' subtext.

I find the Crime-dramas-creating empathy to be only mildly interesting and not that surprising. We've known for a while that Tv, whether by media or actual TV shows, affects those who watch it, so it stands to reason that those who watch Crime-drama shows would pick up on the 'Crime is bad, help those in need' subtext.

If true, can that suggest that glorified violence could affect the number of violent acts?

I feel like I am opening a can of worms by commenting on this reference to violence in media, especially with regards to violent video games. I am sorry in advance, but I do feel like I really want to ask the question.

I have to say, I'm pretty pleased with myself for that opening graphic, if I could be permitted a little immodesty. When John asked if I could do an image for dead frog sex it took me a moment to figure out an angle that wasn't totally inappropriate.

The opening graphic is awesome, I'd love to see a larger version (having trouble reading the last line [something something] Bruce Willis…)

Try refreshing the page, John forgot to enable enlarging the image, I just edited the story, you should be able to click it to see a bigger one. The last line is just apologies to to the 6th Sense people though.

I've been a big fan of arstechnica for a few years now, and became enthused enough to even start posting a while back. This week's weird science renders me besotted. I sometimes send round slightly "off beat" papers to my colleagues to cheer them up when the straight-laced science is having an off-week/month/year. Amongst the several glorious links for this week, the necrophiliac frog link will lift the spirits of many of my friends, I promise. And I thank you.

Funny video but not that surprising. Human eyes will pivot independent of head motion why not owls? Oh wait - their eyes don't move in their sockets (at least several species if not all). Obviously then, their head must be the auto-leveling apparatus.

On the study about intervention, from the description you've given it's not really willingness that they were investigating with the study, it was perceived willingness. It's possible that a proportion of those people would like to think they were the kind of person to intervene, but if the situation came up they wouldn't actually do so. There are ways you could study that response, but it would need to incorporate more than a survey

"We all know how the eye works: picks up light, converts it to nerve impulses, sends it down the optic nerve to the brain, where special areas dedicated to processing it."

I couldn't read past this sentence.... I think you mean "where special areas *are* dedicated to processing it"? Or did you mean to continue the sentence: "where special areas dedicated to processing it have their fun doing that processing."